diagram created by collapsed subprocess is not immediately visible

[schattenk]

Tested on Windows using Camunda Modeler 5.4.1 and Multi-Diagram plug-in 2.0.2

Steps to reproduce:

• create a new BPMN file for Camunda Platform 7
• click on the start event and add a task
• change the task type to "Sub Process (collapsed)"
• open the "Global subprocesses configuration" window

Expected: There should be two diagrams available, since an (empty) diagram was created by the collapsed subprocess.

Actual: There is only one diagram. When the plus button is clicked or when the file is closed and reopened, then the expected diagram appears.